The Australian Government’s independent Climate Change Authority (CCA) is conducting a Caps and Targets Review this year. In this series I will explain why the review is important, outline what I think its recommendations should be, and attempt to deconstruct everything I believe is wrong with the Government’s climate policies and its underlying flawed beliefs about Australia’s role in climate action.
Anthropogenic global warming is the largest and most urgent threat facing humanity today. There is an extremely urgent need for rapid emissions cuts to mitigate climate change. The extent of climate impacts decades, centuries and millennia from now will be determined by policy decisions taken in the near future. The Government’s own Climate Commission has identified the 2010s as the “Critical Decade” for climate change mitigation.[i]
The latest climate science shows scientists have systematically underestimated the impacts of global warming (possibly because they have overcorrected in response to accusations of alarmism).[ii] The Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4) dramatically understates the problem, and AR5 can be expected to do the same because of the conservative nature and inertia of the IPCC process.
There is a high risk that current estimates of climate sensitivity (the degree of global warming associated with a given increase in CO2) are underestimates, as long-term feedbacks could become significant much sooner than expected.[iii]
The atmospheric CO2 level is currently approaching 400 ppm[iv] (compared to the preindustrial 280 ppm), which some climatologists argue is already too high to avoid tipping points for dangerous climate change. The safe level has been estimated as somewhere below 350 ppm, which is associated with ~1°C global warming above preindustrial.[v] The Earth has so far warmed by only 0.8°C[vi] (with further warming to come if atmospheric CO2 remains at or above its present level[vii]), and already the Arctic appears to be crossing a tipping point, implying even 350 ppm is dangerous.
Arctic sea ice is already melting faster in the real world than in the projections that will be included in AR5.[viii] Based on the trend in sea ice volume[ix] and one regional model[x], the Arctic in September could be completely sea-ice-free within a few years. By reversing the surface reflectivity of the northern polar region, the Arctic melt threatens to set off a chain reaction of tipping points, including collapse of the Greenland ice sheet and large-scale release of carbon from melting permafrost.[xi]
The Greenland ice sheet is shrinking at an unprecedented and accelerating rate[xii], and recent modeling suggests the tipping point for total collapse could be a global temperature of around 1.6°C above preindustrial. The lower end of the range of possibilities is only 0.8°C, equal to today’s global temperature.[xiii]
Permafrost is already starting to release carbon and could eventually emit at the same rate as deforestation, a finding which will not be included in AR5.[xiv]
The last time the global temperature was ~1°C above preindustrial (in the Eemian interglacial age 125,000 years ago), the poles were several degrees warmer[xv], there was no summer sea ice in the Arctic[xvi], and sea level was 6-9 meters higher[xvii] [xviii] (meaning at least partial melting of the Greenland and/or West Antarctic ice sheets).
The above findings imply we are already entering a period of dangerous climate change and there is very little time to avoid large feedbacks that could send climate change spiraling out of control.
Because of the long lifetime of CO2 in the atmosphere, before attempting to reduce its concentration, humanity must first stop emitting.[xix] To return CO2 to <350 ppm requires cutting global fossil fuel emissions by 6%/year beginning in 2013 (followed by a global reforestation program later this century to start removing CO2 from the atmosphere). If the world delays until 2020, the required emissions reduction rate would become 15%/year.[xx] At some point the required cuts become so steep they are impossible. In practical terms, everybody needs to cut fossil fuel emissions to zero or near-zero as soon as possible (and eventually less than zero). This means a global phaseout of fossil fuels.
The countries of the world, including Australia, have agreed under the United Nations Framework Convention on Climate Change (UNFCCC) to cut emissions fast enough to avoid “dangerous anthropogenic interference with the climate system”[xxi] and more recently to limit global warming to <2°C.[xxii] As explained above, 2°C is far from a safe target; however, the world is nowhere near on track to achieve even that. A possible global climate agreement has been delayed until at least 2020[xxiii] (and even then it is far from certain to be a globally binding regime[xxiv]). Present voluntary pledges under the UNFCCC, even assuming they are successfully implemented (which is not happening[xxv]), put the Earth on course for an unimaginably catastrophic >4°C global warming by 2100 (plus potentially large feedbacks and post-2100 warming).[xxvi] The “ambition gap” between these pledges and a 2°C pathway is growing instead of shrinking.
There is very little time to shift away from business-as-usual. CO2 is now rising by ~2 ppm/year[xxvii] and emissions are still accelerating: annual global fossil fuel CO2 emissions have risen by 58% since 1990 and rose 2.6% in 2012.[xxviii] The vast majority of the Earth’s known fossil fuel reserves must be left in the ground if humanity is to even meet the agreed goal of limiting global warming to <2°C (let alone reduce CO2 to <350 ppm).[xxix]
Given the mounting evidence that even 1°C of warming is dangerous, it is extremely reckless to be complacent about the world’s present path to >4°C. Human civilization is unlikely to be able to adapt to anything like that level of global warming.[xxx] There is no precedent in human history: global temperature has varied by only a few tenths of a degree in the relatively stable climate of the past 10,000 years in which human civilization developed[xxxi] (though even such small global variation sometimes produced local climate changes large enough to cause or contribute to the demise of local civilizations[xxxii]). When the Earth was 5°C cooler 20,000 years ago, northern Europe and Canada were covered by ice sheets.[xxxiii] It has not been 4°C warmer since Antarctica was ice-free 35 million years ago.[xxxiv]
It is impossible to predict the exact social impacts of climate change, but it is not difficult to imagine unprecedented migrations of hundreds of millions of people, resource wars, and even a collapse of global civilization.
Some argue it is already too late to avert dangerous climate change. Even if that turns out to be correct, we must act now to limit the damage by decarbonizing the global economy as fast as possible. In case it is too late, geoengineering to remove CO2 from the atmosphere on a large scale and/or cool the planet now also warrants serious consideration, albeit as a last resort.
In Part 2, I will explain the importance of the Caps and Targets Review and how CCA should approach it.
This series was first posted on
[i] Climate Commission, The Critical Decade: Climate science, risks and responses, Commonwealth of Australia (Department of Climate Change and Energy Efficiency), 2011, viewed 22 February 2013, http://climatecommission.gov.au/wp-content/uploads/The-Critical-Decade_July-revision_Low-res.pdf
[ii] D Nuccitelli, ‘Climate scientists erring on the side of least drama’, Skeptical Science (blog), 30 January 2013, viewed 21 February 2013, http://www.skepticalscience.com/climate-scientists-esld.html
[iii] JE Hansen, M Sato, P Kharecha, D Beerling, R Berner, V Masson-Delmotte M Pagini, M Raymo, DL Royer, & JC Zachos, ‘Target atmospheric CO2: Where should humanity aim?’, Open Atmospheric Science Journal, vol. 2 (2008), pp. 217-231, viewed 21 February 2013, http://arxiv.org/abs/0804.1126
[iv] Earth System Research Laboratory, ‘Recent Global CO2’, Trends in Atmospheric Carbon Dioxide, US National Oceanic and Atmospheric Administration, 2013, viewed 21 February 2013, http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html
[v] J Hansen, P Kharecha, M Sato, F Ackerman, PJ Hearty, O Hough-Guldberg, S-L Hsu, F Krueger, C Parmesan, S Rahmstorf, J Rockstrom, EJ Rohling, J Sachs, P Smith, K Steffen, LV Susteren, K von Schuckmann, & JC Zachos, ‘Scientific case for avoiding dangerous climate change to protect young people and nature’, Proceedings of the National Academy of Sciences, in press, viewed 12 August 2012, http://arxiv.org/abs/1110.1365
[vi] J Hansen, R Ruedy, M Sato, K Lo, ‘Global surface temperature change’, Rev. Geophys., vol. 48 (2010), RG4004, http://pubs.giss.nasa.gov/docs/2010/2010_Hansen_etal.pdf
[vii] G Schmidt, ‘Climate change commitment II’, RealClimate (blog), 2 June 2010, viewed 22 February 2013, http://www.realclimate.org/index.php/archives/2010/06/climate-change-commitment-ii/
[viii] D Spratt, ‘Arctic sea-ice melt record more than broken, it’s being smashed’, Climate Code Red (blog), 25 August 2012, viewed 21 February 2013, http://www.climatecodered.org/2012/08/arctic-sea-ice-melt-record-more-than.html
[ix] S Carana, ‘How British government’s climate forecasting MET Office gets the Arctic wrong’, Climate Code Red (blog), 20 September 2012, viewed 21 February 2013, http://www.climatecodered.org/2012/09/how-british-governments-climate.html
[x] D Spratt, ‘All gone by 2015? Welcome to the Arctic end times’, Renew Economy, 30 August 2012, viewed 21 February 2013, http://reneweconomy.com.au/2012/all-gone-by-2015-welcome-to-the-arctic-end-times-44411
[xi] Neven & K McKinney, ‘Why Arctic sea ice shouldn’t leave anyone cold’, Arctic Sea Ice Blog, 26 August 2012, viewed 21 February 2013, http://neven1.typepad.com/blog/2012/08/wasislac.html
[xii] M-J Viñas, Satellites See Unprecedented Greenland Ice Sheet Surface Melt, NASA, 24 July 2012, viewed 21 February 2013, http://www.nasa.gov/topics/earth/features/greenland-melt.html
[xiii] A Robinson, R Calov, & A Ganopolski, ‘Multistability and critical thresholds of the Greenland ice sheet’, Nature Climate Change, vol. 2 (2012), pp. 429-432, viewed 21 February 2013, http://www.sciencemag.org/content/335/6071/956
[xiv] B Cubby, ‘At the edge of disaster’, Age, 28 November 2012, viewed 21 February 2013, http://www.theage.com.au/national/at-the-edge-of-disaster-20121127-2a5xe.html
[xv] J Hansen & M Sato, ‘Paleoclimate implications for human-made climate change’, Climate Change at the Eve of the Second Decade of the Century: Inferences from Paleoclimate and Regional Aspects: Proceedings of Milutin Milankovitch 130th Anniversary Symposium, 2012, pp. 21-47, viewed 22 February 2013, http://arxiv.org/abs/1105.0968
[xvi] Climate Commission, Loss of Arctic sea ice indicates global risks from climate change, 2012, viewed 13 November 2013, http://climatecommission.gov.au/wp-content/uploads/Climate-Commission-Arctic-sea-ice-summary.pdf
[xvii] RE Kopp, FJ Simons, JX Mitrovica, AC Maloof & R Oppenheimer, ‘Probabilistic assessment of sea level during the last interglacial stage’, Nature, vol. 462 (2009), pp. 863-867, viewed 21 February 2013, http://www.nature.com/nature/journal/v462/n7275/full/nature08686.html
[xviii] A Dutton & K Lambeck, ‘Ice volume and sea level during the last interglacial’, Science, vol. 337 (2012), pp. 216-219, viewed 21 February 2013, http://www.sciencemag.org/content/337/6091/216.abstract
[xix] G Schmidt, ‘Climate change commitment II’, RealClimate (blog), 2 June 2010, viewed 22 February 2013, http://www.realclimate.org/index.php/archives/2010/06/climate-change-commitment-ii/
[xx] J Hansen, P Kharecha, M Sato, F Ackerman, PJ Hearty, O Hough-Guldberg, S-L Hsu, F Krueger, C Parmesan, S Rahmstorf, J Rockstrom, EJ Rohling, J Sachs, P Smith, K Steffen, LV Susteren, K von Schuckmann, & JC Zachos, ‘Scientific case for avoiding dangerous climate change to protect young people and nature’, Proceedings of the National Academy of Sciences, in press, viewed 12 August 2012, http://arxiv.org/abs/1110.1365v3
[xxi] United Nations, United Nations Framework Convention on Climate Change, 1992, viewed 9 September 2012, http://unfccc.int/resource/docs/convkp/conveng.pdf, p. 4.
[xxii] United Nations Framework Convention on Climate Change, ‘The Cancun Agreements: Outcome of the work of the Ad Hoc Working Group on Long-term Cooperative Action under the Convention’ in Report of the Conference of the Parties on its sixteenth session, held in Cancun from 29 November to 10 December 2010, United Nations, viewed 12 August 2012, http://unfccc.int/resource/docs/2010/cop16/eng/07a01.pdf
[xxiii] United Nations Framework Convention on Climate Change, ‘Establishment of an Ad Hoc Working Group on the Durban Platform for Enhanced Action’ in Report of the Conference of the Parties on its seventeenth session, held in Durban from 28 November to 11 December 2011, United Nations, viewed 12 August 2012, http://unfccc.int/resource/docs/2011/cop17/eng/09a01.pdf
[xxiv] M Levi, ‘A misplaced climate celebration in Durban’, Energy, Security, and Climate (blog), 11December 2011, viewed 12 August 2012, http://blogs.cfr.org/levi/2011/12/11/a-misplaced-climate-celebration-in-durban/
[xxv] Climate Action Tracker, Emissions gap looks set to increase if government action doesn’t step up, Climate Analytics, 2012, viewed 12 August 2012, http://climateactiontracker.org/news/126/Emissions-gap-looks-set-to-increase-if-government-action-doesnt-step-up.html
[xxvii] Earth System Research Laboratory, ‘Recent Global CO2’, Trends in Atmospheric Carbon Dioxide, US National Oceanic and Atmospheric Administration, 2013, viewed 21 February 2013, http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html
[xxviii] Global Carbon Project, Global Carbon Budget 2012, 3 December 2012, viewed 21 February 2013, http://www.globalcarbonproject.org/carbonbudget/12/files/CarbonBudget2012.pdf
[xxix] Carbon Tracker Initiative, Unburnable Carbon: Are the world’s financial markets carrying a carbon bubble?, 2011, viewed 9 September 2012, http://www.carbontracker.org/linkfileshare/Unburnable-Carbon-Full1.pdf
[xxx] Climate Commission, Avoiding the Unadaptable: a 4°C world, Australian Government, 2012, viewed 22 February 2013, http://climatecommission.gov.au/others/avoiding-unadaptable-a-4-degree-celsius-world/
[xxxi] J Hansen & M Sato, Earth’s Climate History: Implications for Tomorrow, NASA Goddard Institute for Space Studies, 2011, viewed 22 February 2013, http://www.giss.nasa.gov/research/briefs/hansen_15/
[xxxii] M Medina-Elizalde & EJ Rohling, ‘Collapse of Classic Maya civilization related to modest reduction in participation’, Science, vol. 335 (2012), no. 6071, pp. 956-959, viewed 21 February 2013, http://www.sciencemag.org/content/335/6071/956
[xxxiii] J Hansen & M Sato, ‘Paleoclimate implications for human-made climate change’, Climate Change at the Eve of the Second Decade of the Century: Inferences from Paleoclimate and Regional Aspects: Proceedings of Milutin Milankovitch 130th Anniversary Symposium, 2012, pp. 21-47, viewed 22 February 2013, http://arxiv.org/abs/1105.0968
[xxxiv] J Hansen & M Sato, ‘Paleoclimate implications for human-made climate change’, Climate Change at the Eve of the Second Decade of the Century: Inferences from Paleoclimate and Regional Aspects: Proceedings of Milutin Milankovitch 130th Anniversary Symposium, 2012, pp. 21-47, viewed 22 February 2013, http://arxiv.org/abs/1105.0968